WASHINGTON (AP) — Homeland Security Secretary John Kelly says members of Congress who don't like the Trump administration's aggressive approach to immigration enforcement should change the laws or "shut up."

Retired General John Kelly has been confirmed as Secretary of Homeland Security, a sprawling department responsible for everything from domestic antiterrorism to border security and disaster prevention. REUTERS/Joshua Roberts Homeland Security Secretary John Kelly says members of Congress who don't like the Trump administration's aggressive approach to immigration enforcement should change the laws or "shut up."

The tough-talking retired Marine general made his remarks in a speech Tuesday at George Washington University, painting his Homeland Security staff as victims who have been tried in the "court of public opinion" or used as "political pawns."

Kelly said critics, particularly lawmakers, are too quick to assume the worst of Homeland Security employees who are enforcing laws intended to keep America safe.

"It stopped on January 20," said Kelly, after adding that his officers have suffered "disrespect" and "contempt" by people outside the department.

Critics say the agency is too heavy-handed in enforcement operations, including arresting undocumented immigrants in the U.S. who do not have criminal records.

Since Trump signed a travel ban banning entry for people from seven Muslim-majority countries and cracked down on deportation of undocumented immigrants, protests have erupted in cities all over the US. Many have said that these laws unjustly target groups of people and tear apart immigrant families.

Kelly did not take kindly to the criticism, saying members of Congress who don't like US immigration laws "should have the courage and skill to change the laws. Otherwise they should shut up and support the men and women on the front lines."

But for too long, the men and women of my Department have been political pawns. They have been asked to do more with less, and less, and less.

In many ways similar to the treatment suffered by law enforcement over the last few years, they are often ridiculed and insulted by public officials, and frequently convicted in the court of public opinion on unfounded allegations testified to by street lawyers and spokespersons.

If lawmakers do not like the laws they've passed and we are charged to enforce—then they should have the courage and skill to change the laws. Otherwise they should shut up and support the men and women on the front lines. My people have been discouraged from doing their jobs for nearly a decade, disabled by pointless bureaucracy and political meddling, and suffered disrespect and contempt by public officials who have no idea what it means to serve.

During my confirmation process and in hearings, members of congress, the press and other public officials frequently asked me about the morale problems the Department has experienced over the last few years. My response has simply been -when you discourage, disable, unjustly criticize and default to believing the self-serving accusations of a wrong doer rather than the DHS police official at the point of the action, and focus disrespect on an individual for doing his or her job, what else do you expect?

It stopped on January 20.

My people—the men and women of the Department—do a difficult and at times nearly impossible job in the service of the American people. They deserve our nation's thanks and respect. They deserve to be proud of the jobs they do.

We are moving in exactly the right direction.

Why? Because the best way to improve morale is to let employees do the jobs they were hired and trained to do, and recognize them for doing it.